Previously, fluorescence activated cell sorting (FACS) has been the standard way to isolate subpopulations of cells, particularly in the field of hematopoietic stem cells. However, FACS has been limited for use in many cases in which there are not specific markers for the cells of interest, such as isolating neuronal progenitors or astrocytic progenitors from neural stem/progenitor cells due to the unavailability of specific cell surface markers for the subpopulations of cells. FACS devices are, however, very expensive and occupy a large amount of space in the laboratory. FACS devices require expensive and complicated lasers in addition to requiring labels and antibodies to perform the FACS analysis.
DEP has been used to separate certain types of cells in solution. For example, Gascoyne et al. demonstrated the DEP separation of MDA-231 human breast cancer cells from blood. Gascoyne et al., Dielectrophoretic Separation of Cancer Cells from Blood, IEEE Trans Ind Appl., Vol. 33, pp. 670-78 (1997). DEP has also been used to sort neurons from a heterogeneous population of mouse-derived neural stem and progenitor cells (NSPCs) and neurons. See Prieto et al., Frequency discretization in dielectrophoretic assisted cell sorting arrays to isolation neural cells, Lab Chip, 12, pp. 2182-89 (2012). DEP has also been used in the sorting of neuron progenitors and astrocyte progenitors form NSPCs. See Nourse et al., Membrane Biophysics Define Neuron and Astrocyte Progenitors in the Neural Lineage, Stem Cells, 32, 706-16 (2014). NSPCs are heterogeneous populations of self-renewing stem cells and more committed progenitors that differentiate into neurons, astrocytes and oligodendrocytes. Due to the present lack of cell surface markers in the field, there are no universal strategies to enrich neuronal progenitors by removing astrocytic progenitors. There is a need for such a solution, including one that does not rely on any particular cell surface marker.